Experimental Methods to Study the Thermochemistry of Gas Phase Ions and Ion-Molecule Reactions

Abstract

Ionic species and ion–molecule reactions provide, in one way or another, a major contribution to the Earth’s chemistry. Although the most familiar reactions occur in solution (where they are often significantly moulded by solvent interaction) there are a number of important areas where ions exist and react in the gas phase. The upper atmosphere is an obvious and important example (0(2). An even more hospitable environment for free ions lies outside the Earth, in outer space. It is only just being revealed how important such reactions are in the creation and propagation of interstellar clouds (3). Gas phase ion–molecule reactions also occur in flames (4) electrical discharges (50). and are sometimes a corrosive nuisance in the coolant gases of nuclear reactors, Finally, they have become an important tool in analytical mass spectrometry (6).